A stone’s throw from the river in Hebden Bridge town centre Jill and Kathryn make a discovery under their eaves: House Martins have arrived. A summer of ups and downs follows and we track events over the year to learn more about the lives of these ‘epic’ little migrant birds, and how to love a ‘pile of poop’. We also find out more about Britain’s other Spring arrivals swifts, swallows and sand martins, and how to tell them apart.